An existing electronic toilet can achieve rectum flushing, anus cleaning and flushing, and water discharged therefrom is supplied from a hot water tank. The hot water tank forms a circulating waterway together with a circulating water pump and a seat. The temperature of the flushing water is achieved by controlling the work of a heating tube of the hot water tank. When the water temperature is adjusted from a high temperature to a low temperature by a user, such a temperature reduction can be achieved by the system only after discharging high-temperature hot water in the hot water tank through a spray bar first and then replenishing cold water, or after natural cooling of the water in the hot water tank. Both methods fail to realize rapid reduction of the water temperature.